1. Preheat oven to 200°F (93°C) and line a baking sheet with parchment paper.

2. Ensure bowl and beaters are clean and dry to prevent grease contamination.

3. Whip egg whites on low speed until foamy, add cream of tartar, then increase speed to medium-high.

4. Gradually add sugar, one spoonful at a time, until mixture is glossy and stiff peaks form.

5. Add vanilla extract and beat briefly to combine.

6. Transfer meringue to a piping bag with a large round tip and pipe ghost shapes onto the prepared sheet.

7. Use a toothpick dipped in black gel food coloring or melted chocolate to dot eyes on each ghost.

8. Bake for 1 hour 30 minutes, then turn off oven and let cookies cool inside with the door ajar for 1 hour.

9. Store completely cooled cookies in an airtight container at room temperature.